Single Storey Extension Planning Permission: Building Your Extension

Adding new rooms to your home can prevent you from having to relocate and try to sell your property. The good news is that single storey extension planning permission is usually not needed and adding your new rooms to your home will be quite straightforward.

Single Storey Extension Planning Permission: When Planning is Not Needed

Building an extension without having to apply for planning permission is easy. Just adhere to the rules. First and foremost, the ground area that is covered by your new extension cannot be more than half of the area of the existing property. This includes other properties that lie within the boundary of your home, and could include an old outhouse.

To avoid having to apply for planning permission, ensure that no part of the roof of your extension is higher than the roof of your existing build. This is quite easy to stick to if you have a two storey home, and if you have a bungalow, a flat roof will ensure you stick to this rule. The eaves of your extension also must not be higher than those of your existing build. To be sure, always make sure you use a reputable extension builder who will plan your building work with the help of an architect.

The eaves can also not be any more than 3 metres on height, and they must not be within 2 metres of the boundary of your property. No part of your extension can extend beyond any wall of your property that faces a road, or that of the principal or side elevation of the original build.

Single Storey Extension Planning Permission


If you want to avoid single storey extension planning permission, then you need to be careful with the materials you use for your build. Unless your extension is a conservatory, the exterior of your extension should be in keeping with your property. This means using materials that are similar.

If your extension is going to include a window, this window must be obscure glazed if it is within 15 metres of the boundary of another home. This rule refers to extensions built on two levels. These windows must be non-opening, unless they are at least 1.7 metres above the floor of the room in question.

Rules Specific to Single Storey Extensions

When you extend your home on only one level, the extension must not go beyond the original wall of your home by more than 4 metres for detached homes and 3 metres for semi-detached and terraced dwellings. For single storey extensions, the overall height of your new build must not exceed 4 metres. No part of your new extension can be within less than 3 and a half metres of your property boundary when there is a road opposite the rear boundary of your home.

Listed Buildings

If you live in a period home, conservation area, or listed building, these rules do not apply. For advice on whether you can extend your home, get in touch with conservation builders sourced by Bristol Builders Network today. Extending a period home is possible, just as long as permission is granted and the rules and regulation are adhered to.

Living in a period home is a privilege and not one that you should abuse. Any extension that you make to your home should not dominate your property. It should be built discretely, and in keeping with your property. It should not be obvious from a distance that your home has been extended. Cottages and bungalows often have modest extensions, often to accommodate bathrooms that were outside when originally built.


It is easy to extend your home without having to apply for single storey extension planning permission. By adhering to the rules and adding an extension that is in keeping with your home, you will save yourself both time and money in the long run.

A single storey extension can add much-needed space to your property. You could use your new room as an open kitchen-diner, or you could make a study, guest bedroom, or dining room. Kitchen extensions are very popular, most especially with older homes. In older homes, the kitchen was often built as a small galley-style room. Opening up this room and extending it to the rear of your home can allow you to create not just much-needed space, but also a great new hub and meeting point for your family home.

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